The MPLS WG Archive

[Robert Raszuk <raszuk@cisco.com>]

Hi Roger,

 > If they are present in the same UPDATE, and it also has a BGP Extended
 > Community attribute (Type code= 16) would the MP_UNREACH_NLRI also be
 > interpreted as, for those VRFs which are importing those route
 > targets?

Nope. For unreachable information in any address family none of the 
attributes (incl BGP ext community attribute) are important and not 
considered. Remember that the NLRI format there still is RD:IPv4 so it 
uniquely identifies all by itself which remote destinations became 
unreachable.

In other words checking against RTs would be required on the withdraw 
only if any other PE would inject new set of RTs for previously 
advertised VPNv4 routes before withdrawing those apriori. That would be 
an illegal operation.

Cheers,
R.

 > Roger Pottier wrote:
 >
> Hi,
>  
>  RFC 2858 (Multiprotocol Extensions for BGP) specifies how MP_REACH_NLRI
>  and MP_UNREACH_NLRI is carried in a packet. Can a single BGP Update 
> packet contain both MP_REACH_NLRI (Type code = 14) and MP_UNREACH_NLRI 
> (Type code=15). I saw an implementation, sending both the path 
> attributes in the same
>  UPDATE.
>  
> If they are present in the same UPDATE, and it also has a BGP Extended 
> Community attribute (Type code= 16) would the MP_UNREACH_NLRI also be interpreted 
> as, for those VRFs which are importing those route targets?
>  
> Roger
> 
> ------------------------------------------------------------------------
> Do you Yahoo!?
> Yahoo! Small Business $15K Web Design Giveaway 
> <http://us.rd.yahoo.com/evt=23609/*http://promotions.yahoo.com/design_giveaway/static/index2.html> 
> - Enter today